1. Field of the Invention
The invention relates to a pad of a composite material to be used with shoes for hoofed animals, especially horses. The hoof pad of this invention is leather-like in that it is breathable like leather, and has superior cushioning and shock absorbing characteristics compared to leather hoof pads; however, the composite hoof pad of the invention exhibits superior dimensional stability, maintains a proper balance of rigidity and flexibility during useful life and resistance to cracking and embrittlement, which attributes leather hoof pads lack.
2. Description of the Related Art
For many years, farriers have inserted pads of various shapes, sizes and materials between a horse's hoof and a horseshoe. The primary purposes for using such pads are: to protect the sole of the horses's hoof; to act as shock absorbers and reduce concussion when the horse's hoof and horseshoe strike the ground; to change the angle of the hoof relative to the ground; and to prevent snowballing.
Hoof pads are generally shaped to be secured, mechanically and/or chemically, between a horseshoe and at least the outer, peripheral portion of the horse's hoof. The two most common shapes of hoof pads are "full" pads and "rim" pads, although other shapes are possible. "Full," sometimes called "flat," pads cover the entire bottom surface of the horse's hoof and are used to protect the hoof and to keep it free of snow and debris. "Rim" pads fit between a horseshoe and the hoof, and are generally about the same size and shape as a horseshoe so that only the outer, peripheral portion of the hoof is covered. Rim pads are used to put more distance between the sole and the ground. Shock absorbing pads, which are used to reduce concussion and vibrations to the hoof and leg structures of the horse, have been made in both full and rim styles and have been made from a variety of materials.
The materials used in prior hoof pads include leather, rubber, polyurethane and other molded plastics, and woven and pressed felts. Leather was one of the first materials used for hoof pads, and leather hoof pads continue to enjoy popularity among farriers and horse owners. In many ways, leather hoof pads have been the standard against which other materials are measured. Leather hoof pads have good cushioning and shock absorbing characteristics. Leather is also "breathable," and permits gas and water vapor transmission throughout the product. This characteristic is particularly important because proper moisture balance around the hoof is essential to the healthy physiology of the hoof.
However, leather hoof pads suffer from a number of significant disadvantages including loss of cushioning and a lack of dimensional stability under compressive stress. Even though leather can absorb and desorb moisture, when leather is alternately wetted and dried, it changes shape. Thus, leather hoof pads subjected to wet conditions and/or compressive stress, which are inevitably encountered by most horses' hooves, will irreversibly change shape. Further, after being subjected to wet conditions, leather hoof pads can become brittle and hard and can crack upon drying.
To overcome the dimensional instability and structural deterioration problems of leather, hoof pads have been made from a variety of molded synthetic materials including rubber, polyurethane and plastics. Although these molded synthetic materials are more dimensionally stable and resistant to deterioration due to moisture than leather, molded synthetic hoof pads are gas and moisture impermeable and are not breathable. Molded rubber, polyurethane and plastic hoof pads trap moisture between the hoof and the hoof pad, which may lead to weakened hoof structure as well as provide an unhealthy breeding ground for bacteria, fungi and yeast. In addition, many molded synthetic hoof pads can be unyielding and inflexible, and can also transmit too much heat from the horseshoe to the hoof.
Woven and pressed felt materials, which are gas and moisture permeable, have been used for some specialized hoof pads but are extremely compressible, lack rigidity, and are generally unsuited for long term use or for use as full pads.
Accordingly, a need remains for a hoof pad having the leather-like qualities of breathability, cushioning and shock absorbency without the dimensional instability, lack of rigidity and other disadvantages of leather. The hoof pads of the present invention satisfy this need, as discussed hereinafter, in an ecologically advantageous way.